I have extra wires available in the bundle. I need one to run a C wire, as the new tstat stays lit, and also uses WiFi. Since I have an additional wire available I guess I'll try it and see if it makes a difference.
Yuri, thanks for the tip about checking the electrical section in the manual. I found a diagram in the manual which shows that if I use W2, "if wire is connected, dip switch No 1 on furnace control should be set to ON position to allow thermostat to control furnace staging". The dip switches are clearly marked 1, 2, 3 and off/on, so I'll flip #1 on and give it a try. If I don't like it, or don't notice a difference, I'll switch it back.
Thanks for all the advice, all! I've never done any of this before, but I'm learning a bunch!

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Apparently you are supposed to make sure the furnace is NOT calling for heat after flippin it and on it's first startup. Like a computer which it is it checks those dip switch positions and burns them to memory. If it is calling for heat it will use the old position irregardless of the new switch position.

Apparently you are supposed to make sure the furnace is NOT calling for heat after flippin it and on it's first startup. Like a computer which it is it checks those dip switch positions and burns them to memory. If it is calling for heat it will use the old position irregardless of the new switch position.

Have the tstat set to OFF, not heat or cool or fan ON and power OFF when flipping the switch. Nothing must be asked to run when you first power it up. That is also good practice when starting any furnace after changing a board.